Am I overreacting/thinking about my coworker coming to work in the infant room with her 4 month old daughter?

One of my coworkers is coming back from maternity leave and she is being put into my room (infants) with her 4 month old daughter. I’m shocked honestly, and highly annoyed as they waited to put the schedule out till literally 5 mins ago! I guess to avoid anyone saying anything. She moved a good worker from my room and I just don’t know what to do now. I really hope this isn’t gonna blow up in face (though I won’t be surprised if it does).